This invention pertains to a changeable-configuration three-dimensional geometric device formed as an articulated structure including four right tetrahedrons and one equilateral tetrahedron. While, as will be explained, the proposed device has a number of possible different uses, one particular use, described herein, is as a piece of child's playground-type equipment.
Structures which are articulated, and whose configurations can be changed infinitely and at will, hold a great deal of interest for people, and especially for children. With such a device, the usual child's imagination can conceive of the device as embodying or representing a host of different kinds of exciting places and/or things.
A general object of the present invention is to provide an articulated device of the type generally outlined, which is visually exciting and pleasing, and is subject to manipulation into an infinite number of different, unique configurations.
According to a preferred embodiment of the invention, the proposed device includes four right tetrahedrons, along with a single equilateral tetrahedron. Hinges are provided that interconnect these five units into an articulated structure which can be adjusted into an infinite number of different configurations. In particular, the hinging arrangement is such that one of the configurations which is possible is that of an equilateral cube, wherein the equilateral tetrahedron forms what might be thought of as the central core of the cube.
The equilateral tetrahedron has four equilateral triangular faces, and each of the right tetrahedrons includes an equilateral triangular face of substantially the same size as each of the faces in the equilateral tetrahedron.
Other objects and advantages which are attained by the invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.